Mr and Mrs Twitcherly are sparrows; common everyday sparrows. They live in a nest hole excavated in an ancient but statuesque oak tree in the garden of 18 Mulberry Road, by their neighbour, an absent-minded but kindly spotted woodpecker called Lemuel. Their twin sons, Furtive and Fearless, were named by David, the five year old who lived at number 18, according to how they behaved in the garden. Their Great Uncle Ebeneezer invites them to stay with him for a holiday in his great elm, which is several miles from their home. Furtive and Fearless have many exciting adventures whilst there, including an encounter with a dangerous ... Well, I am really sorry, but I have been sworn to absolute secrecy about the ending. Mr Twitcherly assures me that, if you read the book, you will enjoy their adventures and be happy with the outcome.